In 2018, Warehouse 13 had net credit sales of $745000. On January 1, 2018, Allowance for Doubtful Accounts had a credit balance of $15960. During 2018, $29090 of uncollectible accounts receivable were written off. Past experience indicates that the allowance should be 10% of the balance in receivables (percentage of receivable basis). If the accounts receivable balance at December 31 was $148000, what is the required adjustment to the Allowance for Doubtful Accounts at December 31, 2018?